Tetanus is a very serious disease, frequently death
for the mammals and humans. The cause is a toxin produced by the
bacterium Clostridium tetani which normally lives in the soil where
it can survive for many years. The organism can gain entry to the
body via wounds, particularly small puncture wounds which may not
be immediately noticeable. The animal loses the control of its nervous
system, and it results in serious muscular contractions.
Equids are the animals which are the most sensitive to this very
resistant bacillus which is everywhere in the environment - i.e.
: ground, manure... Thus any wound, even tiny can be infected; it
must be disinfected.

Contamination

The bacillus Clostridium tetani is of type anaérophobe,
it can develops only in an environment without oxygen. This bacillus
likes particularly the dead tissue where the blood circulation was
stopped by a wound.
The bacillus tetanus is component normal of the intestinal flora
of equids and other herbivores. When the bacilli are expelled from
the body of equids (manure), the conditions of survival are degraded,
and the bacillus is transformed into spore to resist its new environment
and to wait better conditions of survival.
These spores are extremely resistant: they resist 15 minutes at
100°C, many disinfectants, and they can survive more than 30
years safe from the light.

When an donkey is wounded, the spores can return in contact with
the wound, and the bacillus can then proliferate again. They are
multiplying in the wound, it produces a toxin which is a million
times more toxic than strychnin. This toxin will be fixed by a connection
between the motor nerves and the muscles of the organism and thus
will block the donkey of the nerve impulse by causing violent contractions.

Symptoms

In the donkey the causes of tetanus are multiple. Here, four principal
sources:
- accidental tetanus after having a wound
- surgical tetanus after surgical operation
- tetanus obstetrical by the mare after foaling
- umbilical tetanus to the foal

The first symptoms generally appear after a few days (2-4 in the
very vascularized zones, after a week elsewhere), but the bacillus
can stay as spores in the organism for several months if the conditions
for its growth are not optimal.
These symptoms start as stiffness causing the donkey to move reluctantly,
head and ears are extended, there is evidence of muscular spasms
affecting the muscles of mastication and making eating and drinking
difficult. It becomes hypersensitive with the external stimuli (sounds,
light, touch), and we can note a hypersalivation.
A common method to differentiate the disease of the other neurological
diseases are to check the movement of the third eyelid in the corner
of the eye when we clap our's hands: this one closes in an uncontrolled
way.
The frequency and the power of the muscular spasms increase with
the evolution of the disease, and a fatal outcome occurs when the
spasms and the contractions reach the respiratory muscles.

Prevention - Treatment

There is no treatment to inhibit the toxin when this attacks the
nerves, and the success of the treatment is function down to the
sped of the prognosis. But in spite of powerful treatments, more
than 50% of equids do not survive this disease.
On the other hand, vaccination against tetanic toxin ensures a quasi
total protection.

The vaccination protocol recommended is the following:

First-inoculation

2 injections 1 month interval

1st recall

1 year afterwards

Later recalls

every 3 years or if it is necessary (severe wounds)

On animals not vaccinated or whose last recall is
up more than 3 years, if the animal has a wound or an operation,
we practice the serovaccination. It will be followed by another
injection 3 to 4 weeks later, then an annual recall.

The prevention of the umbilical tetanus can be done with the preventive
serum injected during the first hours of the foal's life.